The invention relates to a locking device for use in association with a cabinet locking system, a multi compartment storage unit and other locking devices.
Many multi compartment storage units and other locking devices, including office furniture and storage fixtures, require locking mechanisms to secure the devices against unauthorized access to their contents. Often, the locking systems include locking bars that secure drawers and flapper covers against unauthorized opening. By way of background, US Pat. No. 4,246,769 issued to McLaughlin is an example of an earlier system used in association with cabinet locking systems. The McLaughlin patent teaches the use of a Z-shaped crank mounted on a locking core. The Z-shaped crank is positioned within a linear track provided within a multi-component arm. The crank is held in place within the linear track by a clip secured near the tip of the Z-shaped crank. It is important that the crank be secured for travel within the linear track. Accidental disconnection of the crank from the multi component arm could result in failure of the locking system.
The system disclosed in the McLaughlin patent and other earlier systems are also prone to other manufacturing or installation problems. For example, the locking systems are often designed for installation within confined spaces along the inner walls of a cabinet structure. Typically, very limited space is provided for installation and operation of the locking system and its components. Workmen who install the locking systems often find it difficult to work within those confined spaces. It is particularly difficult to insert the multi component arm into the proper location of the cabinet or other structure, mate the Z-shaped crank within the linear track, assemble the arm with the locking bars and affix the clip to secure the crank to the arm. The earlier multi component arms often became disassembled while the workmen attempted to install the locking system within the storage structure.
Some of the earlier systems were manufactured with various parts requiring numerous steps to properly assemble those components.
It is desirable that a new locking system be provided to reduce or replace the number of component parts required to assemble the multi component arm. It is also desirable to provide a replacement arm that may be more easily installed without the risk of accidental disassembly of the components of the arm. Similarly, it is preferred that the new locking system provide for improved ease of installation within the locking structure.
The present invention relates to a modular arm for use in a storage unit locking system. The modular arm contains an elongated asymmetrical slot for detachably securing a lock drive shaft with an integral retainer. The elongated asymmetrical slot contains first and second slot portions defining different widths across the longitudinal axis. The first slot portion spans a width less than that of the lock-drive shaft retainer. The second slot portion spans a width greater than that of the lock-drive shaft retainer.
Installation of the improved modular arm and lock housing unit does not require the use of a mounting clip. In addition, installation does not require the use of an internally mounted spring and ball bearing. Special tools are not required in typical installations. If required, the lock housing unit may be promptly detached from the modular arm in those instances where the lock housing unit is in need of repair or other service. For example, the externally mounted spring may be easily compressed to provide for rapid and easy removal of the lock housing unit of the entire cabinet locking system.
By comparison, conventional systems in the prior art often require special tools to permit removal of conventional retainers or springs, or in some cases, considerable physical effort and time are required to remove the retainers or springs from conventional housings.
In one aspect, the invention is a modular arm that defines a longitudinal axis. The modular arm may be used in a cabinet locking system. The modular arm includes first and second arm segments. The arm segments include actuators for operating lock bars positioned adjacent opposing inner walls of the cabinet. The first and second arm segments are operationally connected. One of the two arm segments defines an elongated asymmetrical slot. The slot extends along the longitudinal axis of the modular arm. The elongated slot includes first and second slot portions. The first slot portion defines a width that is less than the diameter defined by the second slot portion. The modular arm also includes a biasing element to urge the first and second arm segments between first and second positions defined along the longitudinal axis of the modular arm. When assembled, the modular arm may be detachably secured to a lock drive shaft of a lock housing assembly. The drive shaft of the lock housing assembly includes a retainer with a defined diameter. The diameter of the retainer is less than the diameter of the second slot portion. However, the diameter of the retainer is greater than the width of the narrower first slot portion.
In another aspect, the invention comprises a modular locking assembly which includes an arm assembly operatively connected to a lock housing assembly. The arm assembly includes first and second arm segments. The second arm segment is operatively connected to the first arm segment. The second arm segment or the first arm segment define an elongated asymmetrical slot that extends along the longitudinal axis defined by the arm assembly. The elongated slot comprises first and second slot portions. A biasing element is provided to urge the first and second arm segments between first and second positions along the longitudinal axis. The lock housing assembly includes a locking core that is operatively associated with an offset crank. The crank includes a lock drive shaft that is operatively engaged with the arm assembly, through the first slot portion, when the arm segments are in the second position. When the arm segments are in the first position, the crank is operatively disengaged, within the second slot portion, when the arm segments are in the first position. The lock housing assembly also includes a retainer having a defined diameter. The diameter of the retainer is greater than the width of the first slot portion. The diameter of the retainer is less than the diameter of the second slot portion.
In another aspect, the invention includes a storage unit. The storage unit comprises first and second lock bars that are slideably mounted adjacent to the inner walls of the storage unit. The storage unit also includes a modular arm and a lock housing assembly.
The modular arm includes first and second arm segments for operatively engaging the corresponding one lock bar of the two lock bars. The first and second arm segments are operatively connected. Either the first or second arm segment defines an elongated asymmetrical slot. The asymmetrical slot defines first and second slot portions. A biasing element is provided to urge the first and second arm segments between first and second positions along the longitudinal axis of the modular arm. The lock housing assembly includes a lock drive shaft that extends through the asymmetrical slot when assembled. The shaft comprises a retainer having a defined diameter. The diameter of the retainer is greater than the width of the first slot portion. The diameter of the retainer is less than the diameter of the second slot portion. The retainer may be withdrawn through the second slot portion when the first and second arm segments are in the appropriate position along the longitudinal axis.
In other aspects, additional features may be provided. The biasing element may take the form of a spring mounted on an exterior portion of one of the arm segments. A detent may also be provided for releaseably securing the first arm segment to the second arm segment. The detent may take the form of a projection on one of the first and second arm segments, and a stop on the other one of the first and second arm segments. When a portion of one of the arm segments is inserted into a receiving channel defined by the other of the arm segments, the projection engages a stop to releasebly secure the arm segments together. Additional embodiments of the invention are also possible.